Piri:
I'm not specifically addressing the issue of rabies vaccine for pilots. But in general, this vaccine is only advised for people at high risk. Lab workers who might handle the virus, workers who contact bats, and travelers like trekkers who go into places where rabies is common.
I wouldn't think that pilot work would qualify.
For US folks, a CDC site called vaccines.gov outlines the indications.
In the UK, your NHS has a similar site with virtually the same indications.
(disclaimer: not an AME)